This invention finds specific application in the field of treating agricultural grain products such as soybeans, corn and cereal grains in processes to condition those grains for more efficient usage as feed products for agricultural purposes such as the feeding of livestock such as cattle and hogs as well as other types of livestock. Food products such as soybeans require significant treatment to place them in a condition where they may be usable as a food product for livestock. Other grains are similarly treated to enhance their effectiveness in development of the nutrients required by the livestock such as dairy cattle in production of milk and in hogs for meat production. The treatment processes also enhance the efficacy of the grain and cereal products in the digestive system of livestock. One particular treating process that has been found uniquely effective in processing of grain such as soybeans as well as corn and other cereal grain is subjecting them to elevated temperatures of predetermined magnitude and particular length of time whereby the nutrients of the grains will be processed to a state where they are more efficient in the providing of the nutrients to the livestock during the course of the digestive process. Additionally, in connection with soybeans, such heat treatment also has the advantage of converting the soybeans to a state where they are more readily digested by livestock and thus substantially enhances their utilization.
Apparatus for effecting heat treatment of agricultural grain feed products have been devised and heretofore utilized, but they have not been found to be as efficient and effective in their operation as is desired. An example of a fluidized bed-type apparatus for treating of such particulate material as grain products is disclosed in U.S. Pat. No. 4,419,834 issued to John F. Scott on Dec. 13, 1983. That patent discloses an apparatus having a closed chamber provided with a perforated bedplate across which the grain products are caused to traverse while concurrently effecting a flow of heated air through the perforated plate to effect heating of the grain products. The heated air not only effects the treatment of the particulate material, but it is also utilized in effecting levitation of the particles thereby resulting in a fluidized bed of material. The fluidized bed facilitates the treatment through producing larger voids or spaces as between the particles whereby the air may more freely flow and will also be able to more thoroughly and completely flow around the individual particles and thus better assure that the process and treatment of the material is more effectively and fully completed.
The structure as disclosed in the Scott U.S. Pat. No. 4,419,834 incorporates a typical construction and component that are found in apparatus having fluidized bed operation. Such structures have typically included a bedplate over which the particulate material is caused to traverse and which is perforated with a relatively large number of apertures of relatively small diameter and having the objective of enabling a sufficient amount of air to flow through the plate and effect the levitation and treatment of the particulate material. In the Scott patent these holes are shown as merely being cylindrical in shape and of a specified size of the order of 3/32" diameter and located on 5/16" center lines to produce an open area that is of the order of 8.75% as stated in the specification of that patent. The cylindrical apertures or holes are typical of known apparatus of fluidized bed-type and this specific structural feature has been found to provide inadequate functioning of the fluidized bed, both as to the levitation as well as effecting of the treatment of the particulate material. One structural disadvantage of the cylindrical holes is that the conveyor devices utilized to cause traversing movement of the particulate material tend to force particles or portions of the particles into the apertures. With the cylindrical configuration of such apertures, the particles or portions thus forced into the holes will be retained through frictional forces and over a period of time will have the cumulative effect of interfering with the airflow to a very substantial extent as to materially interfere with the operation of the apparatus. It is thus required that the operation of the apparatus be interrupted at periodic times so as to permit cleaning of the perforated bedplate.
It is further noted that the cylindrical holes result in an airflow pattern that has not been found to perform with the desired degree of efficacy in effecting treatment of the material or in effecting the levitation of the material to enhance the treatment process.